Luminescent tube



Patented rear-1,1934" 1,949,069 LUMINESOENT 'runn Frederick a. saw. Elizabeth, N. 1., animalio Air Reduction Company, Inc., New York, N. Y., a corporation of New York No 1mm. Application M ca use 5 Claim.

This invention relates to gas-contaming tubes which emit light when energized by an electric current. 7

Such tubes are well known, particularly those it containing neon, which emit a reddish-orange light of great brilliance. Tubes containing various mixtures oi gases and vapors have also been used to produce colors such as blue and green.

It is the object of the present invention to proto ride tubes with mixtures of gases and/or vapors which are caused by the pe of current to emit light oi various ,colors and shades of distinctive duality.

In carrying out the invention I may employ no tubes of the usual term made glass, quartz or trodes may be disposed outside the t, however, with suitable conductors connected to a source oi current.

I have discovered that the quality and characteristics of the light emitted by a neon tube may up be modiiledto e, very marked extent by the addition thereto oi relatively, small amounts 01! other rare gases such as ten and xenon. Thus I ilnd that by uddinu irom to25% of either mypton or xenon m1. es thereoi to the neon no in the tube, the characteristic color of the neon lisht disappeers. The color of the light emitted varies with the nature aud'prflimrtions or the gases used.

The color oi the light emitted by' such tubes us may be modified iurther by theme of colored gas tubes. Thus it amber or yellow glass is used, the light emitted ischanged to yellowish green. If adrop of mercury is introduced to the tube containing such gas mixtures, the mercury is 40 vaporized by the heat resulting from the passage of current through the tube and the vapor mlngles with the gases in the tube. when such a tube is energized, the light emitted is a brillient blue it the tube is made'oi substantially us colorless glass. The color is changed to green when the tube is made 01' amber or yellow glass.

As an example of the invention, prefer to employ a mixture of about 90% neon and 10% or krypton and/or xenon crmixtures oi the latto to! gases. .Ihe Eases may be introduced to and sealed in atube oi the usual construction with mil-able electrodes at a pressure of, for example, '7 to 10 mm. o! mercury. Such a tube may be energized by a current oi from to milliam l8 peresand will glow with a pale rose color. I!

the tube ismade of amber or yellow glass, the color of the light'emitted is yellowish green.

In a tube containing a gaseous mixture or similar composition, I may introduce a drop or merv cury. As soon as the mercury is vaporized by so the heat afforded by the of current therethrough, the color of the light emitted will be blue, provided the tube i 1... e of colorlessglass. It a tube of amber or yellow glass is used, the light emitted is a brt n,

One of the advantagw oi ton and xenon mixed with is that such a mixture produces almost a perfectly even distribution oi radiation throughout the visible Neon, for ce, is dient in blum greens. to The spectrum oi 1 ton is rich in yellow, green end blue. The coinaticn oi neon with ten. in which cert lines of .2 a it we ere tively intense, produces even distribution of radiation, so that the gee may be used adventageousiv with or all colors, perticularly yellow, green and blue. its ability to give 9. blue color is particularly useiul, as a deep blue may be obtained without the use of mercury, which is troublesome and We a tendency to produce dark so spots on the of the tube, t a in a tube which has been run 101' a considerable number oi hours.

Another advantage in the use of 1n 1 ton and xenon ed with neon is that because oi their widely different lecular weights and other atomic properties, 2..- 1r! es in current density in the discharge tube afiect the color of light emitted to a marked extent. For instance, in aglass tube having both large and'small diameters and containing krypton and neon, the light emitted at the large diameter will be pale rose, and at the small diameter it will be pink. Neon and xenon may be used to produce a green light in the section of large diameter, and almost a. white light in the section of small diameter tubing. Be-' cause 01' this variation of color produced by change of current density, color of a given tube may be changed by changing the current through the tube, and a very attractive tube is one in which the current is varied continuously.

It is possible, in accordance with the invention, to produce lights of various colors by proper selection and combination of the gases and vapors employed and of the color oi the tubes which 105 contain the gas mixtures. The invention atiords numerous advantages and particularly the possibility of combining lights of different colors tor display purposes.

Verious ses may be m the details of construction and arrangement 01' the tubes and the compositions of the mixtures employed therein, without departing from the invention or sacrificing any of the advantages thereof.

I claim:

1. A luminescent tube containing neon and a gas of the group consisting of krypton and xenon, the gas from said group being present in an amount sufiicient to alter the color of the emitted light.

2. A luminescent tube containing a gaseous mixture of neon with from 5% to 25% oi a gas of the group consisting of krypton and xenon, the gas from said group being present in an amount suflicient to alter the color of the emitted light.

3. Aluminescenttubecontainingapproximately 90% 0t neon and approximately 10% of a gas of the group consisting of krypton and xenon, the gas from said group being present in an amount FREDERICK R. BALCAR. 

